Swash-plate type compressor for air conditioning of vehicles

ABSTRACT

A swash-plate type compressor for air conditioning of vehicles characterized by a complete, improved structural arrangement wherein the column-shape cylinder blocks themselves combined in an axial alingment form the outer frames of the compressor to establish reasonable manufacturing and use thereof, a simplified sealing structure for junction of the two cylinder blocks by arranging individual but cooperable passages, of the refrigerant circulating in the refrigerating circuit and returned to the compressor, in each cylinder block and an internal lubrication system simplified by the omission of the oil pump and carrying out complete distribution of the lubricating oil to the moving machine parts of the compressor.

United States Patent 1111 3,801,227

Nakayama Apr. 2, 1974 [54] SWASH-PLATE TYPE COMPRESSOR FOR 3,577,8915/1971 Katsuta 417/312 AIR CONDITIONING 0F VEHICLES 3,057,545 10/1962Ransom et a1..... 417/269 2,835,436 5/1958 Steinhagen et a1. 417/269Inventor: Show Nakayama, y Japan 3,361,077 1 1968 Freeman 417/269 [73]Assignee: Kabushiki Kaisha Toyoda FOREIGN PATENTS OR APPLICATIONSJidmhokki Seisakusho, KaYiya-shi, 584,630 4 1955 Canada 417/269Aichi-ken, Japan 610,428 8/1948 Great Britain 417 269 {22] Filed: Oct.13, 1971 I Primary Exammer--W1ll1am Li Freeh 1 1 pp 188,897 AssistantExaminer-Gregory P. LaPointe 301 Foreign Application Priority Data [57]ABSTRACT Oct 17 1970 Japan 4581328 A swash-plate type compressor for airconditioning of Oct: 17: 1970 ra anIIIIIjIIIIIIIIIIIIIIIIIIII 45 91329vehicles chaacterized a 'wmlflete, Mar 24 1971 Japan 4647406 turalarrangement wherein the column-shape cylinder blocks themselves combinedin an axial alingment [52] Us 417/269 form the outer frames of thecompressor to establish [51] Int 27/08 reasonable manufacturing and usethereof, a simpli- [58] Field of ear 74/60 fied sealing structure forjunction of the two cylinder blocks by arran ing individual but cooerable asg P P [56] References Cited sages, of the refrigerantcirculating in the refrigerating circuit and returned to the compressor,in each cylin- UNITED STAT-ES PATENTS der block and an internallubrication system simplified 2,877,653 3/1959 Masnik et 31. 74/60 theomission of the pump and carrying out com- E plete distribution of thelubricating oil to the moving anc er... 3,380,651 4/1968 Niki et a1.417/269 machm? parts of the compressor 3,352,485 11/1967 Niki et al417/269 8 Claims, 10 Drawing Figures I221! 3 I 1241123) 1 w. .7,

106 12o 2o 1' W 726 fix a 'f' A. //-T Oi c "1 ME 6 /og E i 911/ 1%PATENIEI] APR 2 I974 sum 3 or 7 PATENTEDAPR 2 m4 SHEET 5 BF 7PATENVEUAPR 2:914 3801.227

SHEET 7 (IF 7 F/g. 9 (PRIOR ART) SWASII-PLATE TYPE COMPRESSOR FOR AIRCONDITIONING OF VEHICLES The present invention relates to a swash-platetype compressor for air conditioning of vehicles, and more particularly,relates to an improvement of a compressor of a structure wherein thecylinder block itself forms the outer frames of the entire mechanismwith omission of a covering body such as a so-called shell or casing.

With recent enormous expansion of the operational functions of vehicles,attachment of additional parts has been placed under severe limitationregarding their weight and occupying space. In order to meet such recenttrends, the compressors for air conditioning on vehicles are necessarilyrequired to be of compact structure and light in weight as well asefficient in their refrigerating function.

The superiority of the swash-plate type compressors is well appreciatedin comparison with the reciprocal type in the properties of superiorrefrigerating function and less vibration and noise during the usethereof. However, they are accompanied with serious drawbacks such as arelatively bulky structure, heavy weight and increased number of machineparts. Compressors of the non-shell type as mentioned above have beenproposed so as to solve such problems.

The non-shell type compressors of the conventional design are usuallyprovided with structures such that an entire structure is divided intotwo parts, i.e. the front cylinder block and the rear cylinder block, bya plane perpendicular to the cylinder axis, suction and dischargechambers are formed in the both cylinder blocks and the equivalentchambers of the respective blocks are in communication with each otherby combining the two blocks in an axial alignment. Owing to suchstructural feature, separate sealing arrangements must be provided forthe suction chamber, the discharge chamber and the swash-plate chamberat the above-mentioned combining portions. Such separate sealingnaturally results in a complicated structure of the sealing arrangementsand imperfect sealing effect is caused thereby.

It is also necessary to mount an oil supply pump within the structure inconnection with the drive shaft so as to supply lubrication oil fromthe'oil chamber to the respective sliding machine parts. This causes anundesirable increase in the number of the machine parts. This furtherrenders one of the cylinder heads sealing the cylinder blocks verycomplicated in its construction and operation. Further, it is regardedas undesirable and having an increasing effect on the operation cost isthat the oil once stored in the chamber located above the drive shaftmust be conducted down to the oil chamber located beneath the cylinderblocks and the oil must be again positively pumped up therefrom by theoil pump so as to be distributed to the respective bearing parts.

The principal object of the present invention is to provide aswash-plate type compressor wherein the internal spaces of the cylinderblocks are most efficiently arranged so as to form the cylinder blocks,which are major components of the non-shell type compressor, in a columnshape such as is most desirable from the viewpoint of manufacturing anduse.

Another object of the present invention is to provide a simplified sealstructure for junction of the two cylinder blocks by separating passagesof the refrigerant in both blocks from each other.

Another object of the present invention is to provide A further objectof the present invention is to provide a swash-plate type compressorhaving enhanced refrigerating function. 7

Further features and advantages of the present invention will be'mademore apparent in detail in the ensuing description, reference being madeto the accompanying drawings, wherein FIG. 1 is a front view of aconventional rear cylinder block,

FIG. 2 is a perspective view for showing a combination of the blocksaccording to an embodiment of the present invention,

FIG. 3 is a front view of the front cylinder block shown in FIG. 2,

FIG. 4 is a transverse sectional view of an embodiment of the presentinvention including the cylinder blocks shown in FIG. 2,

FIG. 5 is a perspective view showing a combination of the blocksaccording to another embodiment of the present invention,

FIG. 6 is a front view of the front cylinder block shown in FIG. 5,

FIG. 7 is a view taken along the line A-C in FIG. b,

FIG. 8 is a view taken along the line BC in FIG. 6,

FIG. 9 is a sectional view of a conventional flange,

FIG. 10 is a sectional part view of another embodiment of the presentinvention.

Referring to FIG. 1, an outlined structure of the conventional cylinderblock is shown. The cylinder block 1 is primarily composed of acolumn-shaped part 11a and a lower extension 11b which is downwardlyintegral with the column-shaped part 11a. The columnshaped part 11a isprovided with three cylinder bores 10, a suction chamber 18 and adischarge chamber 19, both chambers being located between neighbouringbores. The lower extension 11b is provided with an oil chamber 15. Apair of oil separators 30 is provided between the oil chamber 15 and theinterior of the column-shaped part 11a, and an opening 31 is formedbetween the pair of oil separators 30. The lubricating oil contained inthe refrigerant falls into the oil chamber 15 through this opening 31and is subsequently distributed to respective operational parts by asuitable oil pump not shown in the drawing. The cylinder block isfurther internally provided with a specially profiled sealing member 32so as to keep the interior of the cylinder block air-tight.

Now, referring to FIGS. 2 to 4, an embodiment of the compressor of thepresent invention is shown. The compressor comprises, in its essentialparts, a pair of cylinder blocks, i.e. a front cylinder block 102 and arear cylinder block 101, combined with each other in an axial alignment.This combination is further accompanied by a pair of cylinder heads 103and 104, which are attached to outer ends of the both cylinder blocks101 and 102 in the axial alignment, respectively. The four elements arefirmly combined with each other while keeping a prescribed positionalrelationship. Between the front cylinder head 104 and the front cylinderblock 102, a valve plate 106 is fixedly inserted keeping the prescribedpositional relationship. Another valve plate 105 is for the rear couplealso.

Coaxially passing through the blocks, heads and plates, a drive shaft107 provides a direct connection with a drive part (not shown) of thedrive engine of the vehicle, being rotatably mounted by needle bearings108 provided at the outer ends of the blocks 101 and 102. Near thejunction of both blocks 101 and 102, this drive shaft 107 is providedwith a swash-plate 109 keyed thereon. Bothblocks 101 and 102 areprovided with three bores 110 each as in the case of the conventionalcylinder block shownin FIG. 1. All of the bores 110 run substantiallyparallel to the axis of the drive shaft 107 and are provided with doubleacting pistons 111 slidably inserted therein.

The piston 111 includes a pair of end bosses, which are in close slidingcontact with the inner wall of the bore 1 10, and a connecting part ofthe two bosses. The connecting part has a recess at one side thereofreceptive of the outer fringe of the swash-plate 109. This recess of theconnecting part is engaged with both faces of the swash-plate 109 viaballs 112 and shoes 113 disposed therein. Due to this engagement,rotation of the swash-plate109 causes reciprocal sliding of the piston111 within the bore 110. A pair of thrust bearings 114 is disposedbetween the boss of the swash-plate 109 and the blocks 101 and 102 so asto assume the axial thrust load caused by the pumping action of thepiston 111.

As is seen in FIG. 3, sectional chambers are formed in the spacesenclosed by the neighbouring bores 110 and the outer wall of the blocks101 and 102.'The bottom sector chamber is used for a lubricant reservoir115 and the other two for refrigerant passageways 118.

and 119, which communicate with suction chambers 1 l6 and dischargechambers l 17 of the cylinder heads 103 and 104, respectively. As isshown in FIG. 2, the passageways 118 and 119 are closed near thejunction of the blocks 101, 102 and are in communication with inletports 120 or outlet ports 12] opening at the outer ends of the cylinderblocks 101 and 102. The inlet and outlet ports 120', 121 communicatewith inlet and outlet openings 124, 125

tively.- I

After circulation through the refrigerating circuit, the refrigerantreturns to the compressor and is led into the inlet ports l20vand isdistributed-equally to the refrigerant passageways 118 formed in bothcylinder blocks 101 and 102. So as to provide a space necessary for therotationof the swash-plate 109, the refrigerant passageway 118 is madeup of a smaller part 126 of a smaller transverse cross sectional areaand a larger part 127 of a larger transverse cross sectional areacommunicating directly with the smaller part 126. Passing through theinlet port 120, the refrigerant is introduced into the smaller part 126and is forced to change its direction of flow when it strikes the bottomwall of the smaller part 126. Owing to this compulsory directionalchange, the oil suspended therein is separated from its associatedrefrigerant by the inertia effect. Upon introduction into the largerparts 127, the refrigerant flow is suddenly decelerated due to thesudden increase in the transverse cross sectional area and oil particlesof larger weight are separated from their associated refrigerant flowunder the force of gravity. The above indicated flow is shown by thearrows in FIG. 4, wherein within flanges 122, 123, respecthe solidarrows indicate the inlet mixture, the dashed arrows indicate theseparated oil, and the dash-dot lines indicate the separatedrefrigerant.

The oil content separated from its associated refrigerant andaccumulated at the bottom of the larger part 127 is led into the shaftbore 128 through the oil grooves 129 and is distributed towards asealing member 137, the needle bearings 108, etc. for lubricationthereof.

It is not always necessary to form these oil grooves 129 on the sidefaces of the cylinder blocks 101, 102. They can be formed in any framepart which can provide communication of the larger parts 127 with theshaft bore 128 or on the faces of the valve plates and 106 or may beformed on surfaces of both valve plates and the block ends at thejunction of the blocks 101 and 102.

After separation of the oil content, the oiLfree refrigerant isconducted into the suction chambers 116 of both heads 103, 104 throughthe valve plates 105, 106 located at the outward extension of the largerpart 127 (see FIG. 4). The refrigerant is then sucked into the cylinderbore 1 10 by the operation of a suitable suction valve (not shown).

The compressed refrigerant is then discharged into the dischargechambers 117 of the heads 103, 104 via discharge valves 134, 135, then,into the refrigerant passageways 119 via the conduits of the valveplates 105, 106 and finally towards the outlet opening via the'outletports 121 In connection with this circulation of the refrigerant showninFIG. 2, the arrows show the circulating directions of'the medium, thesolid lines show the discharge system and the dotted lines show thesuction system. The lubricant reservoir 115 formed in the sector spacebetween the neighbouring bores receives the excess of the lubricatingoil and feeds this oil to the swash-plate 109 for lubrication andcirculation. The lubricant reservoir 115 is divided into two chambers bya pair of partitions 130, each of which projects from cylinder block 101or 102, respectively, to be combined with each other at the junction ofboth cylinder blocks so as to prevent possible agitation of thereservoir oil. I t

In combination .with this arrangement, a conduit opening 142a isshown,.which is bored through the partition walls 130 at the junctionthereof. However, it should be understood that the conduit opening 142amay be bored at any portion of the partition 130.

In the understanding of the compressor of the present invention, itshould be noted that the lubricant reservoir is structured optimumlyutilizing the internal space of the cylinder blocks and that therespective refrigerant passageways are in communication with their owninlet and outlet openings with no communication through the junction ofthe respective cylinder blocks.

Although the cylinder blocks are internally provided with the lubricantreservoir and the refrigerant passageways, the mechanical structurethereof is considerably simplified. Further, only sealing arrangementsof a very simple mechanical structure are needed for sealing in relationto the swash-plate and the lubricant reservoir, which are usuallysubjected to low pressure applications. Omission of the conventionalsealing arrangement for the refrigerant passageways greatly contributesto reduction in the danger of gas leakages.

Further, in the oil distributing system of the present invention, therefrigerant under suction is branched into two lines of similar shapemidway of the combined cylinder blocks. Therefore, the oil content inthe refrigerant can be uniformly distributed towards the bores of bothcylinder blocks so as to result in a uniform lubrication effect for bothcylinder blocks. In addition, because the discharge chamber 117 is achamber of increased volume, which forms a part of the refrigerantdischarge system, noise and pulsation phenomenon during the operationcan be effectively minimized.

Referring to FIGS. 5 to 8, another embodiment of the present inventionis shown. In the drawing, parts of similar structure and function tothose of the foregoing embodiment are designated by similar referencenumerals. In the portion of the lubricant reservoir 115 wherein theswash-plate 109 is located, a partition plate 130' is disposed. Thispartition plate 130 is composed of a pair of side plates 140 forconnecting the neighbouring bore walls and a bottom plate 141, whichextends from the side plates 140 towards the junction of both thecylinder blocks 101, 102 and has both sides in close contact with theexternal circular wall surfaces of the blocks 101, 102. By thedisposition of this partition plate 130, the second lubricant reservoir143 is formed within the lubricant reservoir 115. It is also possible toform this second lubricant by making the lower end of the side plate 140elongated so as to closely contact the outer circular wall of theblocks. In this case, the bottom plate 141 can be omitted..Conduits 142are formed through the side plates 140 so as to bring the lubricantreservoir 115 into communication with the second lubricant reservoir143.

The oil content thus separated is then led, via oil grooves 129 whichprovide communication from the larger parts 127 to a shaft bore 128,towards the needle bearings 108, the thrust bearings 114 and theswashplate 109 for the purpose of lubrication of the mechanical parts asin the case of the foregoing embodiment.

After lubrication, the excess of the lubricating oil is splashed intothe second lubricant reservoir 143 due to the centrifugal effect of thethrust bearing 114 and is stored therein. The oil thus stored within thesecond lubricant reservoir 143 is changed into a misty condition bybeing stirred by the rotation of the swash-plate 109 and a part of thismisty oil adheres to the side wall of the swash-plate 109 so as tolubricate the balls 112, the shoes 113 and the thrust bearings 114associated therewith. Further, excess of the oil is discharged andstored in the lubricant reservoir 115 through the conduits 142 due tothe pneumatic differential pressure caused by the rotation of theswash-plate 109.

The oil thus stored in the lubricant reservoir 115 is utilized again atthe starting of the compressor. At the time of starting of thecompressor, the internal pressure of the second lubricant reservoir 143is reduced suddenly due to the rotation of the swash-plate 109, andfoaming of the oil is produced in the lubricant reservoir 115. By thesurge of the oil surface due to this foaming and suction by the pressurereduction in the second lubricant reservoir 143, the oil in thelubricant reservoir 115 flows into the second lubricant reservoir 143through the conduits 142 and effects lubrication of the machine partsdue to the rotation of the swash-plate 109.

As will be understood from the above description, in the compressor ofthe present embodiment, the lubricant reservoir formed in the internalsector space of the cylinder blocks is divided into two parts includingthe second lubricant reservoir 143 by the partition the swash-plate 109is partly enclosed by the second lubricant reservoir 143 and thelubricating oil in the lubricant reservoir 1 15 is free from agitationduring the running of the compressor. Due to this arrangement,undesirable mixing of the lubricating oil with the refigerant can beeffectively obviated, resulting in the enhancement of the refrigeratingeffect and less danger of exhaust of the lubricating oil in thelubricant reser- In addition, this embodiment skillfully utilizes thefoaming phenomenon of the oil at the time of compressor starting, whichhas been conventionally regarded as undesirable, for the lubricationpurpose. So, even at the time of the compressor starting, every machinepart can beeffectively and promptly lubricated'to a satisfactory extent.

Further, the quantity of the oil used in the lubrication is proportionalto the circulating quantity of the refrigerant e.g. the speed of thecompressor. Because the oil pump can be omitted, it is possible to makethe entire structure very compact. In addition, because the refrigerantis led by suction along a shortened course, the resistance to itspassage is lessened, therefore the resultant volumetric efficiency canbe considerably en- I hanced.

A further embodiment of the compressor of the present invention will behereinafter explained, the conventional art being shown in FIG. 9 andthe embodiment of the present invention being illustrated in FIG. 10. Inthe arrangement shown in FIG. 9 the suction flange 50 is provided with arear side suction hole 52, a front side suction hole 53, a conduit 54for connecting both the holes 52 and 53 and another conduit 51connecting to the refrigerating circuit. The conduit 51 is formed in anaxial alignment with the conduit 54 and its diameter is the same as thatof the conduit 54. Owing to this arrangement the refrigerant is led bysuction'through the rear side suction hole 52 and is deflected againstthe wall of the front side suction hole 53 so as to undergo adirectional change. Therefore, the major part of the refrigerant passesby suction into the larger part 127 of the front side through the frontside suction hole 53 and a lesser quantity of the refrigerant passes bysuction into the rear side. Consequently, no uniform distribution of therefrigerant between the front and rear side takes place resulting in thelowering of the cooling function. v

In order to obviate this drawback encountered in the conventionalarrangement, in the arrangement of the present invention, the diameterof the conduit connecting the front suction hole with the rear suctionhole is selected so as to be smaller than that of the one connecting therear side suction hole with the cooling circuit.

In FIG. 10, the suction flange of the present invention is shown indetail. Suction holes 152 and 153 are connected to each other by a frontside conduit 154 and another conduit 151 is disposed in an axialalignment with the conduit 154 so as to connect the rear side suctionhole 152 with the refrigerating circuit. The diameter A of this conduit151 is selected so as to be larger than the diameter B of the conduit154. After passing through the refrigerating circuit, the refrigerantreturns to the compressor and advances towards the rear side suctionhole 152 through the conduit 151 of the large diameter. Due to thedifference in the diameter, a part of the refrigerant is deflectedagainst the wall of the rear side suction hole 152, changes itsdirection of advance and flows into the inlet port 120 through thesuction hole 152. The other part of the refrigerant advances directlythrough the conduit 154 of the smaller diameter and enters the inletport 120 through the front side suction hole 153. Due to thedifferencein the diameters, the distribution of the refrigerant to thefront and rear cylinder can be carried out very uniformly.

Thus, the volumetric efficiency can be equalized and a balancedcompressing operation can result with enhancement of the refrigeratingfunction.

What is claimed is:

1. In a swash-plate compressor having a pair of horizontal axiallyaligned cylinder blocks forming a combined block, a swash-platerotatably mounted between said cylinder blocks, and cylinder headspositioned at the ends of said combined block whereby the combinedblockdefines an outer surface of the compressor, at least three boresaxially extending through said cylinder blocks for slidably retainingcompressor pistons, the bores thereby defining sectors in the blocksbetween adjacent bores; the improvement wherein said cylinder blocks arecolumn shaped, comprising an axially extending lubricant reservoir inthe lowermost of said sectors, suction and discharge chambers in saidheads, axially extending suction and discharge refrigerant passagewaysformed in separate other of said sectors and connected to said suctionand discharge chambers respectively, a partition positioned to dividesaid lubricant reservoir into a plurality of chambers, at least oneconduit positioned to inter-connect said divided chambers, one of saiddivided chambersenclosing a part of said swash-plate.

2. A swash-plate type compressor as claimed in claim 1 wherein saidpartition is axially elongated.

3. A swash-plate type compressor as claimed in claim 1 wherein saidpartition is a vertical partition.

4. In a swash-plate compressor having a pair of horizontal axially'aligned cylinder blocks forming a combined block, a swash-platerotatably mounted between said cylinder blocks, and cylinder headspositioned at the ends of said combined block whereby the combined blockdefines an outer surface of the compressor, at least three bores axiallyextending through said cylinder blocks for slidably retaining compressorpistons, the bores defining sectors inthe blocks between adjacent bores;the improvement wherein said cylinder 4 blocks are column shaped,comprising an axially extending lubricant reservoir in the lowermost ofsaid sections, suction and discharge chambers in said heads, axiallyextending suction and discharge refrigerant passageways formed inseparate other of said sectors and connected to said suction anddischarge chambers respectively, said suction and discharge passagewaysbeing blocked at the junction of said cylinder blocks, and separatesuction and discharge ports connected to said suction and dischargepassageways respectively adjacent said junction of said cylinder blocksand extending to the exterior of said compressor.

5. A swash-plate type compressor as claimed in claim 4 comprising asuction flange having suction holes radially corresponding to saidrespective suction ports of said both cylinder blocks, and communicatingwith each other by a conduit of diameter B which runs concentricallywith a conduit of diameter A communicating said one of suction holes forconnection to a refrigcrating circuit, said last mentioned conduitsbeing in an axial alignment and the value of A is larger than the valueof 8, whereby the amount of sucked refrigerant from'said circuit at bothsuction ports is equalized.

6, A swash-plate type compressor as claimed in claim 4 comprising asuction flange having suction holes radially corresponding to saidrespective suction ports of said both cylinder blocks, and first andsecond concentric conduits in said flange in communication with separatesuction holes, said second conduit being adapted to be connected to arefrigerating circuit, both conduits being in axial alignment and thediameter of the latter being larger than that of the former.

7. In a swash-plate type compressor for air conditioning of vehicles, inwhich the compressor has a pair of horizontal axially aligned cylinderblocks forming a combined block, a swash-plate rotatably mounted betweensaid cylinder blocks, three cylinder bores axially extending throughsaid cylinder blocks for slidably retaining compressor pistons, andaxially extending suc tion and discharge chambers formed betweenneighboring bores, whereby the cylinder blocks define an outer surfaceof the compressor; the improvement wherein said suction and dischargechambers are blocked in the vicinity of the junction of said cylinderblocks, and further comprising suction and discharge ports extendingfrom exteriorly of said compressor to said suction and dischargechambers respectively adjacent the blocked ends of said chambers.

8. A swash-plate type compressor as claimed in claim 7 wherein alubricant reservoir is further provided between a pair of bores and saidlubricant reservoir is divided into a plurality of chambers by means ofa partibers'enclosing a part of said swash-plate.

1. In a swash-plate compressor having a pair of horizontal axiallyaligned cylinder blocks forming a combined block, a swash-platerotatably mounted between said cylinder blocks, and cylinder headspositioned at the ends of said combined block whereby the combined blockdefines an outer surface of the compressor, at least three bores axiallyextending through said cylinder blocks for slidably retaining compressorpistons, the bores thereby defining sectors in the blocks betweenadjacent bores; the improvement wherein said cylinder blocks are columnshaped, comprising an axially extending lubricant reservoir in thelowermost of said sectors, suction and discharge chambers in said heads,axially extending suction and discharge refrigerant passageways formedin separate other of said sectors and connected to said suction anddischarge chambers respectively, a partition positioned to divide saidlubricant reservoir into a plurality of chambers, at least one conduitpositioned to interconnect said divided chambers, one of said dividedchambers enclosing a part of said swash-plate.
 2. A swash-plate typecompressor as claimed in claim 1 wherein said partition is axiallyelongated.
 3. A swash-plate type compressor as claimed in claim 1wherein said partition is a vertical partition.
 4. In a swash-platecompressor having a pair of horizontal axially aligned cylinder blocksforming a combined block, a swash-plate rotatably mounted between saidcylinder blocks, and cylinder heads positioned at the ends of saidcombined block whereby the combined block defines an outer surface ofthe compressor, at least three bores axially extending through saidcylinder blocks for slidably retaining compressor pistons, the boresdefining sectors in the blocks between adjacent bores; the improvementwherein said cylinder blocks are column shaped, comprising an axiallyextending lubricant reservoir in the lowermost of said sections, suctionand discharge chambers in said heads, axially extending suction anddischarge refrigerant passageways formed in separate other of saidsectors and connected to said suction and discharge chambersrespectively, said suction and discharge passageways being blocked atthe junction of said cylinder blocks, and separate suction and dischargeports connected to said suction and discharge passageways respectivelyadjacent said junction of said cylinder blocks and extending to theexterior of said compressor.
 5. A swash-plate type compressor as claimedin claim 4 comprising a suction flange having suction holes radiallycorresponding to said respective suction ports of said both cylinderblocks, and communicating with each other by a conduit of diameter Bwhich runs concentrically with a conduit of diameter A communicatingsaid one of suction holes for connection to a refrigerating circuit,said last mentioned conduits being in an axial alignment and the valueof A is larger than the value of B, whereby the amount of suckedrefrigerant from said circuit at both suction ports is equalized.
 6. Aswash-plate type compressor as claimed in claim 4 comprising a suctionflange having suction holes radially corresponding to said respectivesuction ports of said both cylinder blocks, and first and secondconcentric conduits in said flange in communication with separatesuction holes, said second conduit being adapted to be connected to arefrigerating circuit, both conduits being in axial alignment and thediameter of the latter being larger than that of the former.
 7. In aswash-plate type compressor for air conditioning of vehicles, in whichthe compressor has a pair of horizontal axially aligned cylinder blocksforming a combined block, a swash-plate rotatably mounted between saidcylinder blocks, three cylinder bores axially extending through saidcylinder blocks for slidably retaining compressor pistons, and axiallyextending suction and discharge chambers formed between neighboringbores, whereby the cylinder blocks define an outer surface of thecompressor; the improvement wherein said suction and discharge chambersare blocked in the vicinity of the junction of said cylinder blocks, andfurther comprising suction and discharge ports extending from exteriorlyof said compressor to said suction and discharge chambers respectivelyadjacent the blocked ends of said chambers.
 8. A swash-plate typecompressor as claimed in claim 7 wherein a lubricant reservoir isfurther provided between a pair of bores and said lubricant reservoir isdivided into a plurality of chambers by means of a partition wall, saidwall having at least one conduit communicating said chambers, one ofsaid plurality of chambers enclosing a part of said swash-plate.